Method for applying labels to blow molded articles

ABSTRACT

In the method of making hollow plastic articles wherein a label is positioned in each of a plurality of spaced partible molds in a predetermined array, preforms are positioned in each set of partible molds and the molds are closed and the preforms are blown outwardly to the confines of the molds to apply the label to the resultant hollow plastic article, the method which comprises providing labels on a roll of labels, successively die cutting the labels from the web of the roll and simultaneously delivering each label directly to an endless vacuum conveyor, indexing the endless vacuum conveyor to provide an array of labels on the conveyor which corresponds in spacing to the spacing of the array of molds, engaging the array of labels on the conveyor and removing them from the conveyor and depositing the array of labels in the array of molds.

This invention relates to the application of labels to hollow blownarticles.

BACKGROUND AND SUMMARY OF THE INVENTION

In the making of hollow blown plastic articles such as containers, ithas heretofore been suggested that labels be held in one or more of themold sections by vacuum so that when the parison is blown outwardly intoconformity with the cavity, the label becomes adhered or bonded to thearticle.

The molds are often provided in a plurality of sets of partible molds ina predetermined array and, in order to delivery the labels, a pluralityof magazines are provided, one for each mold half, and an associatedplurality of pick-up and delivery devices function to remove labels fromthe magazines and deliver them to one or both of the mold halves of eachset.

As set forth in U.S. Pat. No. 4,636,166, having a common assignee withthe present application, an apparatus is provided wherein labels aresuccessively removed from a label magazine and positioned in an arraywhich corresponds in spacing to the spacing of the sets of molds. Thelabels are then simultaneously moved in the array from the firstposition to a second position within the open partible molds anddeposited in the molds. The apparatus comprises a magazine forsupporting labels in a stack and an endless belt transfer devicepositioned adjacent the magazine. The belt is indexed in predeterminedspaces corresponding to the spaces of the array of molds. A labelpick-up device removes a label from the magazine and deposits it on theconveyor so that the spacing between the labels on the endless transferconveyor corresponds to the spacing between the sets of molds. Anotherlabel deposit device removes the labels simultaneously from the endlesstransfer conveyor and delivers them between the open partible molds.

Where labels are to be cut from a roll of labels, problems arise becausethe free end of labels tends to move so that when a label is cut fromthe roll, the cut may not be square. These conditions are aggravatedwhen the labels are made of plastic.

In co-pending application Ser. No. 802,117 filed Nov. 25, 1985, and nowU.S. Pat. No. 4,680,000, having a common assignee with the presentapplication, there is disclosed a method and apparatus for applyinglabels in the molds of a plastic blow molding machine of the typewherein a plurality of sets of molds are mounted on a wheel rotatableabout a horizontal axis and the molds are moved toward and away from oneanother to enclose a parison and the parison is then blown to theconfines of the cavity between the mold sections which comprisesremoving labels successively from one or more magazines, depositing thelabels on an endless conveyor which transports the labels to a positionadjacent an open mold and laterally transferring the labels from theconveyor to a position within the molds such that when a mold closesabout a plastic parison and the parison is blown, the labels becomeadhered to the blown plastic bottle.

The use of magazines inherently produces problems. Among these are thecost of magazines, the need to replenish the supply of labels in themagazines and the space required about the container forming machine. Inaddition, when plastic or foam labels are being handled, they aredifficult to stack and handle for placement in the magazines. If thelabels are cut from a web and stacked it is difficult to ascertainwhether they are in proper registry. If the shape of the plastic or foamlabel is complex, the magazines are more complex. After being formed,the plastic or foam labels must be handled in batches or stacks that arenot easily handled.

Among the objectives of the present invention are to provide a method ofapplying an array of labels between partible molds which eliminates theneed for label magazines; which can be used to apply labels of differentmaterials such as paper, plastic and foam; which can be utilized inapplying labels to both sections of partible molds providing two labelsto each mold cavity and which minimizes the manipulative steps andlessens the possibilities of error in positioning the labels in anarray.

In accordance with the invention, the method comprises providing labelson a roll of labels, successively die cutting the labels from the web ofthe roll and simultaneously delivering each label directly to an endlessvacuum conveyor, indexing the endless vacuum conveyor to provide anarray of labels on the conveyor which corresponds in spacing to thespacing of the array of molds, engaging the array of labels on theconveyor and removing them from the conveyor and depositing the array oflabels in the array of molds.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective partly schematic view of an apparatus forperforming the method of the invention.

FIG. 2 is a fragmentary plan view taken in the direction of the arrow 2in FIG. 1.

FIG. 3 is a side elevational view taken from the right in FIG. 2.

FIG. 4 is a front elevational view of FIG. 2.

FIG. 5 is a schematic view of an apparatus for performing a modifiedform of the method.

FIG. 6 is a side elevational view of a die cutting apparatus utilized inthe method.

DESCRIPTION

Referring to FIGS. 1-4, the invention relates to blow molded plasticarticles such as containers wherein labels are applied to sections of aset of molds and the mold sections are closed and heated about heatedparisons or preforms and the preforms are blown outwardly in theconformity with the mold sections causing the labels to be adhered orbonded to the blown articles.

As shown in FIGS. 1-4, the invention is shown as being applied to amethod wherein the invention is particularly applicable to a blowmolding apparatus comprising a wheel 10 which is mounted on a shaftextending horizontally for rotation on a frame (not shown) and aplurality of sets of molds are provided in circumferentially spacedrelation about the wheel 10. Each set comprises a pair of mold sections,a first mold section 11 being mounted on the hub and a second moldsection 12 being mounted in radial alignment with the first mold section11 to open and close the mold. As the wheel 10 rotates, where the moldsare open, an extruder (not shown) delivers a parison between an openmold so that when the mold is closed, the parison can be blown to formthe hollow article such as a container. After blowing, the hollowarticles are removed. The blow molding apparatus is more fully shown inU.S. Pats. Nos. 4,523,904 and 4,549,865, which are incorproated hereinby reference.

The apparatus is shown for delivering two labels, one to the cavity ofeach mold section 11, 12 and comprises a base 36 which supports aconveyor 15. The conveyors 17, 17a deliver the labels successively to apoint adjacent the open mold sections 11, 12 and a label placementmechanism 18, 18a associated with each label mechanism 18, 18a operatesto remove the label and deliver it to its respective mold section 10,11. The aforementioned application Ser. No. 802,117 is incorporatedherein by reference for details of the conveyor and delivery apparatus.

In accordance with the invention, rolls 13, 13a of printed labels supplywebs W, Wa vertically downwardly to rolls to 14, 14a and thenhorizontally over rollers 15, 15a. Die cut mechanisms 16, 16a functionto die cut labels from the web W, Wa and deliver them directly toendless vacuum conveyors 17, 17a. The feeding of the webs W, Wa,operation of the die cut mechanisms 16, 16a and the conveyors 17, 17aare timed to provide the labels on the conveyors 17, 17a in apredetermined spacing so that they are delivered successively to theopen mold sections 11, 12. Thereafter depositing mechanisms 18, 18afunction to deliver the labels to the mold sections.

In the form shown in FIG. 5, the invention is applied to an apparatuswhich includes a plurality of sets of partible molds 20 in a lineararray, that is, in side-by-side relationship. An extruder is associatedwith each set of molds and a head is moved downwardly to receive the endof an extruded tube in a neck mold in the head which is then drawnupwardly to position a preform or parison between the mold sections 21.The mold sections 21 are then closed and the article blown to thedesired configuration within the confines of the mold. Where a label isto be applied, the head supports label deposit devices 23 as hereinafterdescribed which deliver labels to the mold sections. If only one labelis to be applied, a single deposit device 23 is provided for each set ofmolds. The aforementioned U.S. Pat. No. 4,636,166 is referred to for thedetails of the apparatus for removing the labels from the conveyor anddepositing them in the molds and is incorporated herein by reference.

In the apparatus shown in FIG. 5, rolls 25, 25a supply webs Wb, Wchaving labels printed thereon downwardly adjacent endless vacuumconveyors 16b, 16c where die cut mechanisms 16b, 16c cut and deliver thelabels successively to the conveyors 26 which are then indexed in timerelationship to provide an array. Thereafter delivery mechanisms removethe labels from the conveyors and deposit them simultaneously in thearray of the mold sections.

FIG. 6 shows a typical die cutting mechanism which can be used whichcomprises a frame 30 that supports a die 31 having an opening 32 with acutting edge corresponding to the shape of the label L which is to becut from the web. A punch 33 cooperates with die 32 to cut a label.Punch 33 is supported on a plate 34 which is moved by a piston of alarge cylinder 35. A stripper plate 36 is mounted on a plurality ofshafts 37 and is yieldingly urged downwardly by springs 38 interposedbetween plate 34 and stripper plate 36 to clamp the web during cuttingof the label.

I claim:
 1. In a method of making hollow plastic articles wherein alabel is positioned in each of a plurality of sets of spaced partiblemolds in a predetermined array, preforms are positioned in each set ofpartible molds and the molds are closed and the preforms are blownoutwardly to the confines of the molds to apply the label to theresultant hollow plastic article, the method of delivering the labels tothe molds which comprises:providing labels in a web of a roll of labels,moving the web of the roll of labels past a die cutting station,successively die cutting a label from the web of the roll of labels atsaid die cutting station by moving a punch through the web at a rightangle to the web, continuing the movement of said punch at a right angleto deliver said label simultaneously directly onto an endless vacuumconveyor, indexing a remaining portion of the web which has the labeldie cut therefrom past the die cutting station after a label has beendie cut and delivered to said conveyor, indexing the endless vacuumconveyor after each die cut to provide an array of labels on theconveyor which corresponds in spacing to the spacing of the array ofmolds, engaging the array of labels on the conveyor and removing themfrom the conveyor, and; depositing the array of labels in one section ofthe array of molds.
 2. The method set forth in claim 1 including thesteps of:providing labels in a web on a second roll of labels, movingthe web of said second roll of labels past a second die cutting station,successively die cutting the labels from the web of the second roll oflabels at said second die cutting station by moving a second punchthrough the web at a right angle to the web, continuing the movement ofsaid second punch at a right angle to deliver said label simultaneouslydirectly onto a second endless vacuum conveyor, indexing a remainingportion of the web which has the label die cut therefrom past the diecutting station after a label has been die cut and delivered to saidsecond conveyor, indexing the second endless vacuum conveyor after eachdie cut to provide an array of labels on the second conveyor whichcorresponds in spacing to the spacing of the array of molds, engagingthe array of labels on the second conveyor and removing them from thesecond conveyor, and; depositing the array of labels in one section ofthe array of molds. 3.The method set forth in claim 2 wherein said moldsections are moved in a closed path and the mold sections are movedradially relative to one another.